The device described offers a promising approach to a new method of managing floating debris. It modifies the surface flow of water from a submerged location. The modified flow reduces the accumulation of debris on a pier or other structure. In the event that some debris does adhere to the pier, an oscillating flow acts to dislodge it. The device is inexpensive and is easily installed. It protects the pier from catastrophic conditions which occur during flooding. The cost of routinely cleaning accumulated debris form the pier is also reduced. The device itself requires little maintenance. It thus represents a cost-effective solution to any scour problems caused by floating debris.